Voltage output control means



1965 w.i-|.FR|1"2 ETAL VOLTAGE OUTPUT CONTROL MEANS 2 SheetsSheet l Fi1ed Oct. 29, 1962 OFF LOW HIGH Nov. 2, 1965 w; H. FRITZ ETAL 3,215,891

VOLTAGE OUTPUT CONTROL MEANS Filed 001". 29, 1962 2 Sheets-Sheet 2 12 2 2972 44 Z 2.9 42 34 W k 22 i V 2a a 22 H 30 g4 W5. 42

INVENTORS WILLIAM H.FRITZ NORMAN M. POTTER CLAIR W. REASH BY 64 2 1M? ATTORN Y i United States Patent 3,215,891 VOLTAGE OUTPUT CONTROL MEANS William H. Fritz, Bay Village, Norman M. Potter, Rocky River, and Clair W. Reash, Fairview Park, Ohio, as-

signors to Union Carbide Corporation, a corporation of New York Filed Oct. 23, 1962, Ser. No. 233,551 8 Claims. (Cl. 31550) This application is a continuation-impart of copending patent application Serial No. 835,727, and now US. Patent No. 3,062,986.

The present invention is concerned with improvements in means for selectively controlling the efiective alternating current voltage supplied to heat-producing devices which are insensitive to wave form. More specifically, the invention relates to an improved rectifier element for providing alternate levels of illumination in an electric lamp.

It has now become possible through the use of diode rectifiers of a semiconductor variety to provide practical means for controlling the alternating current voltage to an ordinary single filment incandescent lamp in order to produce alternate levels of illumination. Such voltage control is accomplished by connecting the diode rectifier in series with one of two possible electrical paths leading from a source of alternating current to the lamp. Depending on which path the current is made to flow, either full or reduced illumination is obtained.

Various rectifier elements incorporating a diode rectifier have been proposed for use in an incandescent lamp socket of the conventional Leviton type wherein at least two electrical paths are provided by a multiple-position rotary switch. The disadvantage of rectifier elements so far produced is that when placed in the lamp socket, a portion of the conductive lamp base becomes exposed due to the increased height of the lamp in the socket. Such disadvantage may be avoided by use of an insulating sleeve which extends partially beyond the socket, thus removing any hazards when using the rectifier element. However, the insulating sleeve is inconvenient to use and it is, of course. somewhat detractive.

It is the principal object of the present invention to provide an improved means for selectively controlling the effective alternating current voltages supplied to a heatproducing device which is insensitive to wave form.

More specifically, another object of the invention is to provide an improved rectifier element adapted for use in a conventional lamp socket of the Leviton type, wherein substantially little if any of the conductive base of the lamp protrudes from the socket.

Still another object is to provide an improved rectifier element which is protected from damage due to rotation of the conductive lamp base when the lamp is screwed into the socket.

A further object is to provide an improved rectifier element which is easy to assemble and which is economia cal to manufacture.

Other objects and advantages of the present invention will become apparent from the following description, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a circuit diagram of a device embodying the invention;

FIG. 2 is an elevation, partially in section, of the rectifier element of the invention, shown associated with a lamp and a lamp socket;

FIGS. 3 to 3b are sectional views of a switch associated with the rectifier element, wherein the switch is shown in its various operating positions;

FIG. 4 is an enlarged plan view of the rectifier element of the invention and the lamp socket as shown in FIG. 2, but with the lamp removed, wherein portions of the rectifier element are broken away to show details of its construction; and

FIG. 5 is a section taken along the line 55 in FIG. 4.

Referring now to FIG. 1 of the drawings, there is shown a circuit diagram of a device embodying the invention. As shown, a diode rectifier is connected in series with one of two possible paths leading from a source of alternating current to a given heat-producing element 2, which is insensitive to voltage wave fiorm. Depending on which of the two paths the current is made to flow, either full or reduced performance is obtained from the element 2.

The device above described may be an incandescent lamp assembly as shown in FIG. 2. The lamp assembly there shown comprises an ordinary single filament bulb adapted for mounting in a standard three-way Leviton lamp socket 12, which is of a conventional design except for the presence therein of the rectifier element 14. As shall be described in detail, the rectifier element 14 contains a silicon diode rectifier and is placed within the bottom of the socket 12 in engagement with the pair of contacts 15, 17, respectively, the latter being of the conventional spring contact type. FIG. 2 shows the arrangement of the lamp filament and the end contact 19 of the bulb 10 in relation to the Leviton lamp socket 12 containing the ordinary four-position rotary switch 21. The electrical paths controlled by the swtich are best understood by reference to the schematic circuit diagrams shown in FIGS. 3, 3a and 3b.

In FIG. 2 the points 20 of the Leviton switch 21 correspond to the off position; in FIG. 3 they correspond to dim illumination, since the current passes through the diode rectifier; and in FIG. 3a. bright illumination is obtained for the current bypasses the rectifier. Bright illumination is again secured by turning the switch to the position of FIG. 312, since the rectifier is bypassed.

With reference to FIGS. 4 and 5, the rectifier element 14 of the invention comprises an annular body 22 composed of an insulating material, suitably a thermosetting plastic such as phenol-formaldehyde. The annular body 22 is of a size such as to fit within the socket 12 and has a somewhat conical or inwardly developed surface as at 23 to permit the base and end contact 19 of the bulb 10 to pass therethrough. Within the bottom of the annular body 22 a cylindrical recess 24 is provided for receiving both of the contacts 15, 17 in the socket 12. As will be seen in FIG. 4, the cylindrical recess 24 defines a bottom wall in the annular body 22 as indicated at25. Also provided in the annular body 22 are diametrically disposed slots as at 26, 27, in which a pair of rectangular plugs 28, 29 are mounted. For purposes to be describe-d, the length of each plug 28, 29 is greater than the thickness of the bottom wall in order to permit a portion thereof to project radially into the cylindrical recess 24 as shown at 30, 31, respectively.

Within the annular body 22 a cylindrical recess or cavity 32 is provided and mounted therein is a silicon diode rectifier 34. To make contact with the diode rectifier 34, a conductive ring 35 is provided in the cylindrical recess 24 and a lamp contact element 36 is mounted within the central opening of the annular body 22. As best shown in FIG. 5, the conductive ring 35 is supported on the rectangular plugs 28, 29, and has a tab extension 37 which is mounted in one of the slots 26 and which is secured in electrical contact with the bottom terminal of the diode rectifier 34, suitably by soldering.

The lamp contact element 36 is shaped concavely at its center and is provided with a projection 38 for engaging the end contact 19 of the bulb 11). To support the contact element 36, there are provided thereon a pair of diametrical support members 39, which are mounted in the annular body 22, one of which members 39 is secured in electrical contact with the top terminal of the diode rectifier 34, also suitably by soldering. As shown in FIG. 5, both of the support members 39, 40 are mounted in notches 41, 42 provided in the rectangular plugs 28, 29, and are shaped to correspond to the surface 23 on the annular body 22. Both the conductive ring 35 and the lamp contact element 36 are suitably made of metal, such as copper, for example.

When the rectifier element 14 is placed in the socket 12, the contacts 15, 17 are received within the cylindrical recess 24 in the bottom of the annular body 22. The spring contact 17 engages the bottom of the lamp contact element 36 just beneath the end contact 19 of the bulb 10, while the contact 15, which is radially disposed in the socket 12, engages the conductive ring 35. Thus it will be seen that two possible paths are provided for current flow, i.e., one through the spring contact 17 and the lamp contact element 36 to the bulb filament, and the other through the contact 15, conductive ring 35, the diode rectifier 34 and the lamp contact element 36 to the bulb filament, the formercorresponding to bright illumination and the latter to dim illumination of the bulb 10.

It will be apparent from the above that the rectifier element 14 of the invention may be placed in the bottom of the socket 12 without substantially increasing the height of the lamp bulb 10. Furthermore, it is evident that the rectifier element 14 is easy to construct and may be manufactured economically.

Another important feature of the present invention is the provision of means for preventing damage to the rectifier element 14 due to its rotation when the bulb is screwed into the socket 12. Such means are provided by the rectangular plugs 28, 29 which project radially into the cylindrical recess 24 of the annular body 22. Thus when the bulb 10 is placed in the socket 12, rotation of the rectifier element 14 is prohibited by engagement between one of the plugs 28, 29 and the contact in the socket 12 as shown in FIG. 4.

In the practice of the present invention, most any diode rectifier of a small size may be used. Silicon rectifiers are most suitable, although others may be employed such as germanium rectifiers. With the use of silicon rectifiers, advantages are found in that the rectifier can be operated without damage at temperatures as high as 350 F. so that the heat from the lamp will not effect its performance. While the present invention has been described mainly with reference to light dimming, the rectifier element is suitable for use with any device which is insensitive to voltage wave form, such as heating pads or other heatproducing elements where it is desired to provide at least two ranges of heat output.

What is claimed is:

1. A rectifier element adapted for use in combination with a single filament incandescent lamp having an end contact in the base thereof and a standard three-Way socket having a pair of contacts therein, comprising an annular body composed of an insulating material, said annular body being of a size such as to fit within said socket and having a cylindrical recess in the bottom thereof adapted to receive said contacts in said socket, said cylindrical recess defining a bottom wall in said annular body, a pair of diametrically disposed slots in said bottom wall, a cavity in said annular body, a diode rectifier in said cavity, a contact element in the central opening of said annular body, said contact element having a pair of support members mounted in said annular body, one of which support members is secured in electrical contact with one terminal of said diode rectifier, a conductive ring provided in said cylindrical recess adapted to engage another of said contacts in said socket, said conductive ring having a tab extension mounted in one of said slots and secured in electrical contact with the other terminal of said diode rectifier, and a pair of plugs provided in said slots, the length of each of which is greater than the thickness of said bottom wall, whereby portions of said plugs project radially into said cylindrical recess for en- 4 gaging one of said contacts in said socket to prevent rotation of said rectifier element.

2. The rectifier element of claim 1 wherein said annular body has an inwardly developed surface thereon to accommodatesaid base and end contact of said lamp;

3. The rectifier element of claim 1 wherein said contact element is shaped concavely and is provided with a projection for engaging said end contact of said lamp.

4. In combination, an incandescent lamp having an end contact, a lamp socket having a base, and in said base a multiple-position rotary switch having contacts in said socket, and a rectifier element, said rectifier element comprising an annular body composed of aninsulating material, said annular body being of a size such as a fit within said socket and having a cylindrical recess in the bottom thereof adapted to receive said contacts in said socket and an inwardly developed top surface to accommodate said base and end contact of said lamp when said lamp is mounted within said socket, a cavity in said annular body, a diode rectifier in said cavity, a concavely shaped contact element in the central opening of said annular body engaging one of said contacts in said socket on one side thereof and said end contact of said lamp on the other side thereof, said contact element having at least one support member mounted in said annular body and secured in electrical contact with one terminal of said diode rectifier, a conductive means provided in said cylindrical recess engaging another of said contacts in said socket, said conductive means having a portion thereof mounted within said annular body and secured in electrical contact with the other terminal of said diode rectifier, said rectifier element being adapted to pass to said lamp a rectified current through said conductive means, said diode rectifier and said contact element in one position of said switch and a full wave alternating current directly through said contact element in another position of said switch while bypassing said diode rectifier, thereby providing alternate levels of illumination in said lamp.

5. In combination, an incandescent lamp having an end contact, a lamp socket having a base, and in said base a multiple-position rotary switch having contacts in said socket, and a rectifier element, said rectifier element comprising an annular body composed of an in-,

sulating material, said annular body being of a size such as to fit within said socket and having a cylindrical recess in the bottom thereof adapted to receive said contacts in said socket, said cylindrical recess defining a bottom wall in said annular body, a pair of diametrically disposed slots in said bottom wall, a cavity in said annular body,

a diode rectifier in said cavity, a contact element in the central opening of said annular body engaging one of' said contacts in said socket on one side thereof and said end contact of said lamp on the other side thereof, said contact element having at least one support member mounted in said annular body and secured in electrical contact with one terminal of said diode rectifier, a conductive ring provided in said cylindrical recess engaging another of said contacts in said socket, said conductive ring having a tab extension mounted in one of said slots and secured in electrical contact with the other terminal of said diode rectifier, and a pair of plugs provided in said slots, said plugs having a length which is greater than the thickness of said bottom wall defining radially projecting portions for engaging one of said contacts in said socket to prevent rotation of said rectifier element,-

said rectifier element being adapted to pass to said lamp a rectified current through said conductive ring, said diode rectifier and said contact element in one position of said switch and a full wave alternating current directly through said contact element in another position of said switch while lbypassingsaid diode rectifier, thereby providing alternate levels of illumination in said lamp.

6. The combination of claim 5 wherein said rectifier element has an inwardly developed surface on said annular body to accommodate said base and end contact of said lamp.

7. The combination of claim 5 wherein said contact element is shaped concavely and is provided with a projection for engaging said end contact of said lamp.

8. In combination, an incandescent lamp having an end contact, a lamp socket having a base, and in said base a multiple-position rotary switch having contacts in said socket, and a rectifier element, said rectifier element comprising an annular body composed of an insulating material, said annular body being of a size such as to fit within said socket and having a cylindrical recess in the bottom thereof adapted to receive said contacts in said socket and an inwardly developed top surface to accommodate said base and end contact of said lamp when said lamp is mounted within said socket, said cylindrical recess defining a bottom wall in said annular body, a pair of diametrically disposed slots in said bottom wall, a cavity in said annular body, a diode rectifier in said cavity, a concavely shaped contact element in the central opening of said annular body engaging one of said contacts in said socket on one side thereof and said end contact of said lamp on the other side thereof, said element having a pair of support members mounted in said annular body, one of which support members is secured in electrical contact with one terminal of said diode rectifier, a conductive means provided in said cylindrical recess engaging another of said contacts in said socket, said conductive means having a portion thereof mounted within said annular body and secured in electrical contact with the other terminal of said diode rectifier, and a pair of plugs provided in said slots, said plugs having a length which is greater than the thickness of said bottom wall defining radially projecting portions for engaging one of said contacts in said socket to prevent rotation of said rectifier element, said rectifier element being adapted to pass to said lamp a rectified current through said conductive means, said diode rectifier and said contact element in one position of said switch and a full Wave alternating current directly throughsaid contact element in another position of said switch while bypassing said diode rectifier, thereby providing alternate levels of illumination in said lamp.

References Cited by the Examiner UNITED STATES PATENTS 3,028,525 4/62 Morton 3l5272 DAVID J. GALVIN, Primary Examiner.

JAMES D. KALLAM, Examiner 

1. A RECTIFIER ELEMENT ADAPTED FOR USE IN COMBINATION WITH A SINGLE FILAMENT INCANDSCENT LAMP HAVING AN END CONTACT IN THE BASE THEREOF AND A STANDARD THREE-WAY SOCKET HAVING A PAIR OF CONTACTS THEREIN, COMPRISING AN ANNULAR BODY COMPOSED OF AN INSULATING MATERIAL, SAID ANNULAR BODY BEING OF A SIZE SUCH AS TO FIT WITHIN SAID SOCKET AND HAVING A CYLINDRICAL RECESS IN THE BOTTOM THEREOF ADAPTED TO RECEIVE SAID CONTACTS IN SAID SOCKET, SAID CYLINDRICAL RECESS DEFINING A BOTTOM WALL IN SAID ANNULAR BODY, A PAIR OF DIAMETRICALLY DISPOSED SLOTS IN SAID BOTTOM WALL, A CAVITY IN SAID ANNULAR BODY, A DIODE RECTIFIER IN SAID CAVITY, A CONTACT ELEMENT IN THE CENTRAL OPENING OF SAID ANNULAR BODY, SAID CONTACT ELEMENT HAVING A PAIR OF SUPPORT MEMBERS MOUNTED IN SAID ANNULAR BODY, ONE OF WHICH SUPPORT MEMBERS IS SECURED IN ELECTRICAL CONTACT WITH ONE TERMINAL OF SAID DIODE RECTIFIER, A CONDUCTIVE RING PROVIDED IN SAID CYLINDRICAL RECESS ADAPTED TO ENGAGE ANOTHER OF SAID CONTACTS IN SAID SOCKET, SAID CONDUCTIVE RING HAVING A TAB EXTENSION MOUNTED IN ONE OF SAID SLOTS AND SECURED IN ELECTRICAL CONTACT WITH THE OTHER TERMINAL OF SAID DIODE RECTIFIER, AND A PAIR OF PLUGS PROVIDED IN SAID SLOTS, THE LENGTH OF EACH OF WHICH IS GREATER THAN THE THICKNESS OF SAID BOTTOM WALL, WHEREBY PORTIONS OF SAID PLUGS PROJECT RADIALLY INTO SAID CYLINDRICAL RECESS FOR ENGAGING ONE OF SAID CONTACTS IN SAID SOCKET TO PREVENT ROTATION OF SAID RECTIFIER ELEMENT. 